1. Field of the Invention
The present invention relates to a medication filling apparatus for filling a container such as a vial or a bag with medications (the medications hereinafter mean tablets, capsules, pills, lozenges, and any other solid medications) in a quantity specified by a prescription at a hospital or the like.
2. Description of the Related Art
Conventionally, at a hospital or a pharmacy, medications prescribed by doctors are supplied to patients by using a medication feeding machine as disclosed, for example, in Japanese Examined Utility Model Publication No. 57-7660 (B65D83/04). More specifically, medications in a quantity specified by a prescription are dispensed one by one from a tablet case using a dispensing drum and the dispensed medications are collected by a hopper, a conveyor, etc., then packaged with packaging paper.
In this case, the side surface of the dispensing drum in the tablet case is provided with a plurality of vertical grooves, i.e. aligned holes, so that the medications such as tablets, capsules, pills, and lozenges are admitted from the tablet case to the grooves and aligned in a single line in each of the grooves. Under this condition, the dispensing drum is rotated to let the medications fall out of the groove when the groove is aligned with an outlet, i.e. a dropping hole.
The medications falling through the outlet are counted by a sensor; when the number of the dropped medications reaches a quantity specified by the prescription, the dispensing drum is stopped, thus filling a container with a predetermined quantity of medications.
In a configuration where a groove permits two medications to enter therein vertically, there is a danger that the two medications drop at the same time through the outlet. To prevent this from happening, a conventional apparatus is provided with a separator which juts out in the groove as disclosed in the aforesaid publication so as to allow only one medication to drop at a time.
The separator is made of a plate-shaped member such as sheet metal which is thin but resistant to deformation because it is used to separate the medications, e.g. two medications, which have been vertically aligned in the groove provided on the rotating dispensing drum and to let the medications drop one by one. Thus, when the groove is aligned with the outlet, the separator separates the single medication which is in the lowermost position, i.e. the one to drop, from the medication above it so that the lowermost medication is permitted to fall while the medication above it is prevented from falling.
The aforementioned tablet case, dispensing drum, etc. are usually composed of synthetic resin primarily to enhance safety, obviate complicated manufacture processes, and protect medications from being scratched. Further, medications include many capsules; therefore, when the dispensing drum is rotated, static electricity is generated from the friction between the rotating dispensing drum and the medications, or among the medications, or between the tablet case and the medications, thus electrifying the medications.
As described above, the conventional apparatus employs a hard thin plate-shaped material as the separating plate, presenting a problem in that the separating plate scratches or chips medications.
There has been another problem: depending on shape and size of medications, if the medications which have been vertically aligned and fed in the groove are shifted vertically at their contact point, the separating plate would be caught on the side surfaces of the medications, clogging the medications and preventing them from being dispensed. For this reason, a plurality of different types and mounting positions of the separating plates have been conventionally prepared or the mounting position has been made adjustable, so that the separating plate may be changed or adjusted in position to make the separating plate exactly positioned between the vertically aligned medications according to the type of medications placed in the tablet case. Thus, extremely cumbersome work has been required in the conventional apparatus.
There has been still another problem: if the medications in the tablet case are electrified, then the medications, which are generally extremely lightweight, stick to the inner surface of the tablet case or the dispensing drum. As a result, the medications do not fall even when the dispensing drum rotates.
Moreover, the conventional apparatus is designed so that the aforesaid outlet of the medications is always open and therefore the medications are sometimes over-dispensed due to the inertia force of the dispensing drum. The chance of such over-dispensing increases greatly especially when the rotational speed of the dispensing drum is increased to shorten the filling time.
In particular, outside air comes into the table case through the outlet at all times, leading to a problem in that the medications absorb humidity and deteriorate or degrade. There has been another problem in that medications accidentally drop through the outlet, which is kept open at all times, when the tablet case is detached or attached for filling it with medications or for cleaning it.